Automatically controlled electric circuit



Dec. 3, 1935. J. L. JONES AUTOMATICALLY CONTROLLED ELECTRIC CIRCUIT 2Sheets-Sheet 1 Filed Oct. 25, 1932 F'lyl. L

Dec. 3, 1935. J. L. JONES AUTOMATICALLY CONTROLLED ELECTRIC CIRCUITFiled 001;. 25, 1932 2 Sheets-Sheet 2 By a.

Patented Dec. 3, 1935 UNITED STATES ,VPATENT OFFICE 2,023,051AUTOMATICALLY CONTROLLED ELE CIRCUIT James L. Jones, Washington, I). C.Application October 25, 1932, Serial No. 639,491

10 Claims.

which operate automatically to cut-oi! the electric current to a deviceoperated thereby during its idle periods should they exceed apredetermined length of time.

Another important object is to provide means to carry out the principlesof the invention in apparatus, for example, welding apparatus, in aself-contained unit, particularly to enable the improvements to beincorporated into or installed in the usual wiring of known apparatus sothat such wiring will suffice without additional or materiallyadditional wiring and further enable one to overcome the use of specialswitches, wiring and supports for the same used at the present time tocontrol (especially at a distance) the flow of operating current.

A vfurther object is to provide a circuit which enables the local orremote starting of operation of a generator or other source of powermerely by closing a switch, preferably located convenient to anoperator, or grounding the welding electrode or other device by usingthe existing welding or other power circuit as the starting circuitalso, being especially adaptable to arc welding where an operator isfrequently required to work at a considerable distance from the sourceof power.

Various additional objects and advantages will in part be pointed outand otherwise become ap-- parent from a consideration of the descriptionfollowing taken in connection with accompanying drawings.

In said drawings each of Figures 1 to 8 is a diagram of a difierentelectric circuit or apparatus embodying the invention and Figure 9 is anelevation of a self-contained arc welding outfit or apparatusconstructed in accordance with the invention.

Referring first to the form of Figure 1, a motor generator set is shownat A, having an electric motor I, adapted to drive a generator Iathrough the medium of a shaft 3. Electric energy from any suitablesource conventionally shown as a generator 2, passes through feed lines4, containing a magnetic switch 5, normally held in an open position bya spring 5a, as shown, by gravity or in any desired manner. A doublepole switch is shown, but any number of poles may be used, however, asis'necessary to suit the source of current.

Said generator Ia, has one pole grounded as at Go and a conductor 1leads from its other polarity to a device which utilizes electric energyas for instance an arc welding electrode 8, which coacts with but ismechanically disconnected from work 9, such as metal being welded andwhich is grounded as at I0.

Where grounded circuits are shown in the diagrams, insulated circuitsmay be substituted in 10 the conventional manner.

The said magnetic switch 5 is automatically closed in starting anoperation by grounding the electrode 8. To this end switch 5 iscontrolled by an armature I I, surrounded by a coil I2, grounded at I3.Said coil has a conductor I 4, leading to a contact I5, and movable withthe armature but insulated therefrom at Ilia. When the apparatus is atrest, contact I 5 is in engagement with a stationary contact I6. Aconductor I1 leads from 20 one side of the secondary of a transformer Tto contact I6 and a conductor I8 leads from the other side of thetransformer secondary to the conductor 1. The transformer T isoperatively connected with its primary energized by feed 5 wires 4.

The switch 5 in Fig. 1 is adapted to automatically open either bycurrent or amperage generated by member Ia dropping to a predeterminedamount, occasioned by idleness or failure of application of electrode 8to the work. To this end, a relay SR preferably of the dash pot ordelayed action type is connected in conductor i and coacts with anarmature is. The coil of relay SR is wound so that when the current isabove or at a predetermined amount, or when the voltage thereacross isabove or at a predetermined amount, the armature IS will be held closedagainst a branch conductor it of the conductor I8. From armature I9, aconductor it leads to a contact 22 with which contact I 5 engages in theclosed position of switch 5.

It will be realized that the action of coiiSi't is preferably delayedsufliciently to cause the motor circuit to be opened only afterelectrode d has been removed from contact with work 9 for a shortinterval.

Presuming the circuit or apparatus to be at rest, and the parts in theposition of Fi ure i, opera tion is started by grounding eieztiode itwhich causes current to flow from the source through feeders 4,transformer T, conductors I8 and i, electrode 8, work 9 to ground on theone side and on the other side through conductor I'I, contacts I6 andI5, conductor II and coil I2 to ground. 55

Thus coil I2 is energized and moves armature ll 'so as to close switch 5and engage contacts l5 and 22. Relay SRunder these conditions functionsas a holding coil for switch 5 and the welding process or otherutilization of current from generator 2 may then proceed. When thewelding current is interrupted, the series relay SR moves armature Wfrom engagement with branch conductor to thus break the circuit to coill2 whereupon armature it is retracted and the switch 5 opened and themotor I deenergized.

The invention has practical application in an arc welding outfit orapparatus as shown in Figure 9, it being particularly noted that thesame is a self-contained unit, requiring substantially no additionalwiring over equipment now in use but merely the incorporation of theseveral additional devices therein and particularly avoiding the use ofspecial switches, wiring and parts, usually used, for remote electricalcontrol.

In using the equipment, the electrode 8 may be freely or normallyapplied to and removed from the work being welded, the wiring of therelay SR. permitting the current to decrease to the point where thevoltage of the generator increases or builds up (say to 50 volts) overthe operating voltage (say ii) volts) without opening switch 5. However,the wiring of relay SR will cause the opening of switch 5 upon theelectrode 8 remaining out of working relation with the work for say 30seconds or any other predetermined length of time. an apparatusaccording to the present invention therefore cannot continue to run andconsume energy as in cases where the workman neglects to manuallyoperate a stop switch, due to time consumed and distance it would benecessary to walk to do so or for other reasons.

Electrode i3 is to be considered as a broad showing of any deviceoperated by or consuming electric energy since the principles of theinvention may be equally well applied for example where motors,generators, transformers and the like are used in the circuit instead ofthe electrode.

In Figure 2 a slightly modified form is shown and it'diflfers from theform of Figure 1 only in using a shunt relay 23 wired at 24 and 25across conductors ii and I, to replace the series coil SR.

Another slight modification in Figure 3 consists in replacing thetransformer 'I' of Figure l with a motor generator set consisting of amotor 26, shaft 21 and a generator 28 driven by the shaft from (hemotor.

Figure 4 shows the embodiment of said shunt relay parts 23, 24 and 25 ofFigure 2 and the motor generator, parts 26, 21 and 28 of Figure 3 in thecircuit of Figure 1 in place of the transformer T and series relay SR,respectively.

In the circuits of Figures 1 to 4, the transformer or motor generatormay be eliminated if desired and one side of the feed line grounded asat 29 in Figure 5, the circuit otherwise specifically corresponding tothat of Figure 1.

Figure 6 discloses a form wherein the closing of the motor (1) circuitdepends upon manual operation of a switch 30, rather than throughgrounding of the electrode or equivalent device 8. In this instance, thesaid switch 30 which is preferably of the momentary closed type, thatis, will automatically open, after closing and release of the contacts,connects conductors 3| and 32 leading from feed wires l. In wire 32, amagnetic coil 33 similar to that at I2 is connected to co-act with thearmature H, and switch 5.

The armature I 9 of.the series coil SR is connected by a wire 34 toconductor 32, andit moves to and from a contact 35 on a branch 36 ofconductor 3i, so that coil SR acts as a holding coil for switch 5 afterswitch 30 is released and while cur-rent is flowing in wires ll and I8.Upon interruption of current or increase of voltage in wires ll and i8,armature l9 opens the circuit to coil 33 thereby opening switch 5.

The form of Figure '7 generally corresponds to that of Figure 6 butspecifically differs therefrom in that a transformer 3i is employedacross conductors 3i and 32 and the coil 33 and switch 30 are grounded,respectively, at 38 and 39. Also armature i9 is grounded at 35a.

The modification of Figure 8 generally corresponds to the circuits ofFigures 6 and 'l but employs a switch in one side of the feed line onlyas at M. Switch lli co-acts with contacts ii and 52 of conductors s3and, the latter leading to one of the feed wires. The other ieed wire iincludes a magnetic coil l2 like that at l2 and 33 and a switch 65 likethat at 39, connects conductor 33 and one feed wire i. A conductor d6includes a series relay ll and leads to an electrode or equivalent 8co-acting with metal or work El grounded at l0 as in the previous forms.Conductor 36 is grounded at 18 and a transform- 1 er it is connected tothis conductor and conductor M. Series relay ll corresponds to that a atSR and has a similar co-acting armature at 50 which is wired at 51 toone feed wire 4 and moves to and from a branch 52 of conductor 43. Thuswhen switch is momentarily closed current from the feed lines 4energizes coil l2 thereby closing switch 40 so that the current flowsthrough transformer 49 to the electrode 8 when the latter is grounded.Thereafter the series relay ll and armature control the circuit andfunction to attain the same results as the corresponding parts in theother forms.

Said Figure 9 is to be considered as a selfcontained unit embodying anyof the electric circuits of Figures 1 to 8.

It is obvious that where series relays or shunt relays are employed,either type may be used or that combined series and shunt relays may besubstituted, also that switches may be substituted for relays and thatvarious other changes may be resorted to provided they fall within thespirit and scope of the invention:

I claim;--

1. In combination with a source of electrical energy having a drivingmotor, means to establish an operating circuit from said source, saidcircuit also being the stopping and starting circuit for the drivingmotor, said means including a switchy-and means also energized from saidsource operable to automatically close and hold said switch closedthrough the action of a load in the circuit of thesource of electricalenergy and automatically open said switch after removal of the load fora predetermined time.

2. A power supply system for changing electri- -'cal energy of one formto electrical energy of to the flow of current of a predetermined value

